Drill-head and cutter-blade therefor.



Nm 883,137. PATBNTBD MAR. z, 1908.

J. P. KARNS.

DRILL HEAD AND GUTTER BLADE THBREPOR.

I MN /M lf.

9/ .gva/I l NUR/VE Ys PATENTED MAR. 24, 1908.

J. P. KARNS. DRILL HEAD, .ARD/GUTTER; BLADE THERBFO R.

AIWLIGATION PILED JUNE 8,1907.

2 SHEETS-SHEET 2.

y; fi/f7 A TTQRNE Ys there may be a lUNITED sTATEs PATENTI oEElcE.

JOHN PRUE KARS, OFl BOULDER, COLORADO, ASSIGNOR TO THE J. P. KARNS TUNNELING l MACHINE CO., OF BOULDER, COLORADO.`

DRILL-HEAD AND CUTTERFBIJADE THEREFOR.

Specification of Letters Patent.

Patented March 24, i908.

Original application led February 23, 1907, Serial No. 358,867. Divided and this application filed June 8, 190?. Serial No. 377,981.

To all whom tt may concern.'

Be it knownthat I, JOHN PRUE KARNs, a citizen of the United States, residing at Boulder, in the county of Boulder and State of Colorado, have invented a new and useful Drill-Head and Cutter-Blade Therefor', of which the following is a specification. i

;This invention has reference to improvements in drill-heads for drilling machines and cutter blades therefor, and it is designed more articularly for use in connection with a dril ing machine such vas shown and described in my `a plication for Letters Patent No. 358,867, led February 23, 1907, of which this case is a division. In the said application there is shown a drilling machine designed for the drilling of large bores, up to eighteen or more feet in diameter, through ea'rthy and rock formations. In a machine of the larger type the structure is necessarily very massive and is made to stand heavy strains and hammer blows of great force.'

The present invention is directed more particularly to the construction of the drilllead and the cutter blades carried thereby, whereby the drill-head may be made to sustain the eiiiect of heavyblows without injury to `itself and the cutter blades may be so supported that they are unaffected bythe impact of the material at the breast of the tunnel except insofar as they may become dulled by use, and for this` purpose are made read-ily removable so that vthey may be sharpened from time to time.

In addition to these features, the invention comprises means whereby the bore of the tunnel may be maintained sensibly constant, and for this purpose there may be provided rcamer bladesA at the periphery of theI drill-head so adjustably mounted that they may be projected from their seats from time to time to provide for wear. ln order that ractical constancy of the bore of the tunnel produced by the machine all .the reamer blades are made adjustable but some are made more finely adjustable v than others, so that it is not necessary to adjust all the reamer blades fully every time and the saving therefrom is therefore material. For thls purpose a certain small number of the reamer blades may be provided with a fine or delicate adjustment, whereby the wear may be taken up at frequent intervals and in smalll amounts, while the remainder of the reamer blades are provided w1t-h-a coarse or gross adjustment, whereby they may be adjusted step by step, each step in- K that all portions' of the end wall or breast of the tunnel being bored will be acted upon by the teeth on the face of the drill-head.

The invention will be fully understood lfrom the following 'detailed description, taken in connection with the accom anying drawin s forming part of this speci cation, in whic Figure 1 is a face view of the drill-head,

showing but a few of the cutters in position;

Fig. 2 is a central section, with parts -in elevation, of the drill-head; Fig. 3 1s a view of a ortionof one of the reamer blades on a arger scale than shown in Fi s. l and 2; Fig. 4 is a section through one of t e cutter blades and so much of the drill-head as is necessary to show the mode of connecting the cutter blades thereto on about the same scale as Fig. 3; and Fig. 5- is a view of another type of reamer blade, showing the means for producing a iine adjustment thereof on about the same scale as Figs. 3 and 4.

Referring to the drawings, the drill-head consists of a spider of a diameter a little less than the bore of the tunnel to be cut. This drill-head spider comprises a hub 1 from which project a number `of radial arms 2 in-I tegral with a number of concentric rings 3, the outer one of which constitutes the periphery of the drill-head spider. Each arm 2 has formed on its rear face as an integral part thereof a web 4, and each ring 3 has formed on it a rearwardly rejecting web 5. The hub, arms, rings and) one integral whole except that the entire structure may, for convenience in manufacturing, be formed of two halves secured to gether after the manner of split pulleys or webs are all formed as hub 1` About midwayr of the'outer web 5 balance wheels. This latter structure is illustrated in Fig. 1. Each web 4 extends from its corresponding arm to the'rear end of j drill-head to a point near t e web y5 on the outer. ring 3. At this point the web'4 gradually widens until it merges into the web 5 of the outer ring 3, which last-named web extends to the rear so far as the rear edge of the and formed on its inner face so as to project radially inward toward the center of the drill-head is Aa short, strengthening web 6. The structure just described vis such that the drill-head spider is braced in all directions against such strains as. may come against its iront face and the bracing is such that nostrain tha may be brought to bear-on any portion of said front face'will be sufficient to sensibly deflect it from a substantially true. (plane,

The hub 1 is4 provided with a boss 7 projecting beyond the front face of the drill-.

head, and on the iront face'of this boss are mounted cutter blades 8 at right angles to each other and .extending diametricallv across the face of said boss.

Secured to the arms 2 'tangentially to the boss 8 are a number of cutter blades 9 of sufficient'length to span two arms, as shown, and beyond thesetangential blades each arm carries a series of blades 10 parallel to the blades 9, and still further toward the periphery ofthe drill-head each arm has another lset of parallel cutter blades 11, shorter than the blades 10 and set ata slightly ii'atter angle to the arc described by all the blades as the drill-head rotates. Now, it has already been stated that for structural reasons the drill-head may be madev of two halvesgaiiterI the manner ofan ordinary split wheel or pulley, and the meeting edges of these two halves are formed with arms 2 of less width than the other arms 2 but the combined width oijtwo contiguous arms is greater than that of any single arm 2.

elsewhere located. For this reason the cutter blades 9, 10, and 11 secured to these articular arms ar somewhat longer ,than t ose secured to the other arms so as to straddle the intervening space between the two meet- 1n arms.

etween the arms 2 the drill-head is provided With a number of radial cutter bla/des 12 extending from the innermost ring 3 to the next adjacent outer ring 3, and from the latter rin to the peripheral ring 3 are a'number of ot er cutter blades 13, all of which latter are adjustable radially outward and constitute reamer blades, as will hereinafter appear. The several blades of the drill-head are secured to the spider by means best shown in Fig. 4.

periphery of the in the outer face of thev arm 2 is a' groove 14 arranged at a suitable "angle, to receive the in ner ed e of one of the cutter blades, say'a cutter b adel 10. At one side of the groove 14 the arm 2' is formed v-witha ribvl-, not shown in Fig. 4 but clearly shownin Fig. 1, and this rib terminates in anenlargement 16 rear ace ofthe arm 2, which perforation' receives the shank of an L-shaped bolt V17'.

throufgh which extends a perforationl to the That is, this bolt has oneend 18 bent at right j angles' and seated in a perforationfll) in thev cutter blade 10. The other end ofthe bolt 1.7, where it extends through the-innerface of the arm 2, is threaded toreceive a-nut 20 by means of which the bolt r17v is secured tothe arm 2 in a manner to hold the cutter blade 'iirmly seated in the groove 14. By reference to Fig. 1 it will be seen that each blade is held-.to the drill-head by two or more bolts 1,7 'Y

While this forms a secure fastening for the cuttervblades they are at the same time easily removed from the drill-head by unscrewing the nut 20, when the lcutter blades ma be lifted from their seats'and so taken 0H lr'om the drill-head.

All the cutter blades are formed with teeth 21, best shown in Fig. 4'where it will be seen that they are generally frusto-pyramidal in shape with( an elongated rectangular base and an elon ated cutting edge.

Vroo

Those ra 'al cutter blades l13 `which are 'termed reamer blades extend beyond the outer ring 3 vof the drill-headv and are there supported by brackets 22 integral with the' outer ring 3 and projecting outward therefrom in a radial direotion. These brackets y i l have grooves like the groove 14 of Fig. 4 andv also have ribs 15 for receiving and supporting the cutter blades. The brackets 22 servefas sup orts for those portions of the reamer\\ bla es 'which project beyond' the eriphery ,of the outer ring 3. The reamer b ades project radially outward a short. distance beyond the cuter ends of the brackets 22.and thereby provide am )le clearance for the drill-head outside the brackets 22. At the outer ends the reamer blades are rovided with radially projecting reamer teet i 23 in'addition to the teeth 2]., which latter are like those of the other blades. The reamer blades are 'cut away to the rear of the teeth 23, as indicated at 24, so as to provide clearance space and also to provide for the Wear of these teeth. The extent of radial projection of the teeth 23 of the reamer blades beyond the brackets '22 will determine the diameter of the bore .of

the tunnel as cut by the drill-head.,

In the operation of the machine the teeth 23 will be gradually worn .off on their radially outward edges, and provision is therefore made for adjusting the reamer blades radially outward. In order to facilitate the adjustment of these blades there is provided` a fine adjustment for some`of them and a coarse adjustment for others. For instance, a certain'few, say four, of the reamer blades equi-distantljT arranged around the periphery of the drill-head are provided with smooth, longitudinal slots 25, as shown in Fig.- 5, for the reception of the ends 18 of the bolts 17, and the rear faces of these particular blades are' provided with one or more` lugs 26 against which. abuts an adjusting set-screw 27 suitably threaded throu 'h a fixed stud on an appropriate portion o the drill-head. By simply loosening the nuts 2() of the bolts 17 a very delicate adjustment of the four special reamer blades illustrated may be made in a radially outward direction, when the nuts 20 may be again tightened. This adjustment may be made again and again, as occasion may require, and in practice will be made at comparatively frequent intervals.

The rest of the reamer blades 13 are provided with similar slots 28, as best shown in Fig. 3, but instead of these slots being smooth, as shown in Fig. 5, their bottom walls are formed into a series of curved seats -29 all of such size as to receive and seat the heads 18 of the bolts 17. These last-named rearner blades can, therefore, be adjusted only step by step, each step representing a movement equal to the diametric thickness of the head 18 of a bolt 17. Now, by adjusting the reamer blades having the smooth slots the diameter of the bore of the tunnel may be kept substantially true, but the reamer blades provided with the coarse adjustment will be wearing away and becoming shorter and shorter. Ultimately, this wearingv away will be equivalent to the width of one of the seats 2f), or, in other words, to the width of the head 18 of a holt 17. Whenthis occurs, all of those coarsely adjustable reamer blades can be moved radially outward a distance equal to the thickness of the head 18 of a bolt 17 and then again locked in the adjusted posit-ion.

The brackets 22 are provided at the rear with webs 3() integral with the. webs 6, for imparting strength to the brackets, and these webs-aref so spaced as to leave room between them ,Jur the nuts 2() of the bolts 17, which are provided for fastening the. outer ends of the reamer blades to the drill-head.

In order that the teeth of the cutter blades may reach every portion of the surface to be cut, the teeth on adjacent cutter blades are arranged to move, as the drill-head rotates, in arcs inter osed between the arcs described by t 1e teeth of adjacent cutter' blades.

It will be observed that the cutters on the boss 7 project further forward than those on vof ashaft 31 havin the rest ofv the drill-head. This-will cause the drill-head to cut an axial or guiding passage into the end wall of the tunnel in ad- Vance of the main portion of the drill-head, thus serving to lead the drill-head and Amaintain it in the plane of travel determined u on.

The drill-head is supported u on one end a ste per end 32 introduced into the hu 1 and)there held by a pin 33, but this structure need not be here particularly described. since it is fully described in my aforesaid application.

As to the manner of operating the drillhead, it may be here stated that the shaft is reciprocated to the desired extent and slowly rotated step by step and is also fed to the breast of the tunnel as the latter is cut away, and the teeth 21 and 23 operate u on the material to be cut after the manner o a stone masons chlsel.

I cla1m:'-

1. In'a drilling machine, a drill-head provided with radial cutter blades projecting beyond the periphery of the drill-head to constitute reammg members thereof and adjustable radially to maintain a predetermined diameter of cut.

2., In a drilling machine, a drill-head provided with radial reaming cutters having a fine radial adjustment., and other reamlng cutters having a coarse or quick radial adjustment.

3. In a drilling machine, a drill-head provided with cutters adjustable radially beyond the periphery of the drill-head, and provided with adjusting means for the radual projection of said cutters in a radia direction.

4. In a drilling machine, a drill-head having reaming cutters projecting radially beyond the periphery of the drill-head, and

Y means for the adjustment of said cutters step by step radially outward,

5. In a drilhng machine, a drill-head provided with cutters projecting radially outward from the eriphery ofthe drill-head and having means or the fine or gradual adjustment of the same in a radially outward direction, and other cutters projectin radially outward from the periphery ofthe rill-head and having means for the coarse or step by step adjustment of the same radially outward upon the drill-head.

6. In a drilling machine, a drill-head having roaming cutters projecting radially outward from the periphery of the drill-head, slots in said cutters for the reception of securing means and permittin longitudinal movement of said cutters witgh reference to said securing means, adjusting screws for 'moving said cutters gradually outward in a radial direction, and other cutters projecting radially beyond the periphery of the machine and provided. with slots for the reception of securing means, said slots being provided inA means whereby the cutters may be adjuste one wall with a series of seats for said securin radially outward step by step. v

' 7. In a drilling machine, adrillfhead provided with cutter blades, and means forv securing said blades thereto Comprising 'L- shapedl bolts with their Shanks passing through the body of thedrill-head and their` heads engaging inperforations in the cutter blades, i. Y

'8. In a drilling madhine, a drill-head, series of perforated cutter blades seated in grooves formed in the face of said drill-head, and Lfshaped locking bolts having their heads'engaglng in the perforations in the cutter blades and their Shanks projecting through the drillhead to the rear thereof4 and there receiving securing nuts. /v

9. In a drilling machine, a drill-head hav- .ing slotted cutter blades, L-shaped bolts havheads projecting into one of the seats in the slots and their shanks extended through to the rear of the drill-head and there-receiving securin nuts. 4

l1. n a l drilling machine, a drill-head' I.frame'consisting of a hub, radial arms projecting therefrom, concentric rings connect- -1ng`said arms, the outer ring forming the sealer periphery ory the' drill-head frame, rearwardly i L projecting webs lupon the ring, the web of! the outermost. ring having a rearwardfvpro. jection equal. to that or"v thehub and the Webs of the other rings having a less extent ore'arf Ward projection; and radialw'ebs on the arms p extent koi. rear; ward proj ectionV fromY the ubv to near the peripher of the frame and then increasing in having a gradually les'senin'lgv rearwar projection until they merge .into theweb formed on'the outermost ring, all 'the'said Webs, arms and rings 'being integral at meeting points. A

12. In a drilling machine, a drill-head havblades and other radially-disposed toothed blades arrangedv vbetween the "angular seriesV such that of blades, the arrangement bein the paths ofthe teeth of one bla (je are inter-v spersed between the paths of the teeth of the adjacent blades'. y

13'. Ina drilling machine, a drilllhead liavin 1a circular series of spaced groups of' radial y disposed toothed blades, and other radial series of angularly disposed 'toothed blades interspersed between the lgroups of radial blades, the angular disposition of the angularly disposed blades being Hatter toward the periphery of the drill-head than near the center thereof. e

In testimony that I claim the foregoing as i my own, I have hereto aiXed my signature in the presence of two Witnesses.v

n vlrOHN PRUE KARNS. Witnesses: ,y

' JOSEPH I. DrivEREAUX, l

HnNRr L. OBRIEN.

' ing radial series of'angula'rly-disposed toothed r 

